Steam-boiler



2 SheetsSheet 1.

( No Model.) I

H. A. LAU'GHLIN. STEAM-BOILER. No. 509,318. Patented Now-Z1, 1893.

new.

(No ModeL) 2 Sheets- Sheet 2.

H. A. LAUGHLIN.

. STEAM BOILEIL No. 509,318." Patented Nov. 21, 1893.

UNIT D STATES PATENTOFFICE.

HENRY A. LAUGHLIN, OF PITTSBURG, PENNSYLVANIA.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 509,318, dated November 21, 1893.

Application filed April 29,1898,

, To all whom, it may concern:

Be it known that I, HENRY A. LAUGHLIN, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented or discovered-a certain newand usefulImprovement in Steam- Boilers, of. which improvement the following is a specification.

My present invention relates to tubulous or water tube boilers of the general class or type exemplified in Letters Patent of the United States, Nos. 490,119 and 490,120, granted and issued to me under date of January 17, 1893, and its object is to provide a steam boiler of such type, which, by reason of its strength, simplicity, compactness, low center of gravity, and freedom from exterior accessories, shall be conveniently and desirably applicable in marine service.

To this end, my invention, generally stated, consists in the combination of two cylindrical heads, inclined water tubes connecting said heads, a fire chamber intermediate between the heads, and a lower gratein said fire chamher.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a vertical longitudinal central section through a steam boiler illustrating an embodiment of my invention, and Fig. 2, a transverse section through the same, at the line 00, 0c, of Fig. 1.

In the practice of my invention, I provide a front head 1, anda back head 2, each of which constitutes a steam and water receptacle, and is of cylindrical form, having its inner and outer sheets connected by socket bolts or by screw stays 3, as shown. The thickness of the heads 1 and 2 is preferably made greater than that which would suffice for the circulation of water, in order to provide steam spaces of considerable volume in the upper portions of the heads. Said steam spaces are connected by a pipe 22, which opens into the heads 1 and 2, in or about in their vertical central plane, to which pipe, the main steam supply pipe leading to the engine, and the safety valve casing, may be connected.

The heads 1 and 2 are set at such distance apart as to afiord space between them for a fire and combustion chamber of the length desired, at or near the bottom of which a fire Serial No. 472,299. (No model) grate 7, which may be of any suitable and preferred form, is fitted, and which is provided, at top, with an opening, to which a stack 11 is connected.

The heads 1 and 2 are connected, at lower and higher levels by inclined Water tubes 15, which are, as in Letters Patent Nos. 490,119 and 490,120 before referred to, arranged in vertical rows, those of the alternate rows bein g inclined in relatively opposite directions. The ends of the tubes 1.5 are expanded into the inner sheets of the heads 1 and 2, which are preferably inclined so as to be at right angles to the tubes, and the tubes are inserted and removed through openings closed by removable plates in theouter sheets of the heads.

A horizontal diaphragm or circulating plate 25 is secured between the inner and outer sheets of the heads 1 and 2, a short distance above the lower ends of the upper rows of water tubes, and extends across .the heads from points between the outer rows of tubes and the adjacent portions of the shells, upwardly and downwardly extending circulating plates 28, 27 being secured to the inner and'outer sheets of the heads at the ends of the plates 25. By reason of the inclined water tubes and the circulating plates, a natural circulation of Water is induced and maintained in the boiler, as in the patents before referred to.

The tire and combustion chamber between the heads 1 and 2, is closed, at its ends, by the heads, and by lower corner plates, and at its top and sides by a- D shaped wall 7*, which is preferably formed of light sheet metal, lined with fire brick or tile, and may be cased with wood or any suitable and preferred nonconducting covering. The portion of the wall 7 above the center of the heads 1 and 2, is preferably semi-circular, and substantially concentric with, and of similar radius to the shells of the heads, and the portions of the wall below the center of the heads are substantially tangential to their shells, and may be either parallel with or outwardly inclined to their vertical central plane. The grate may thus be made of a width nearly equal to or, if desired, even greater than, thediamete'r of the heads, while the upper width of the fire chamber can be reduced so that it shall not project beyond the contour of the cylindrical heads. In lieu of forming the fire door openings in one or both of the heads, they may be located in one or both of the side walls of the fire chamber, so as to afiord convenient access to all parts of the grate.

Access is had to the fire chamber through openings 12 in the front head closed by suit able doors, or through openings through the side walls as before stated, and an ash pan 14 is provided below the grate. Where tubes of sufficient length are employed to render it desirable, firing openings and doors may be provided in both heads, or in the side walls, and a central fire bridge may be interposed between two end grates, as in Letters Patent No. 490,120 aforesaid. A feed water heater 10 of any suitable construction, may be located in the fire chamber, above the tubes 15.

The boiler is supported upon bearers 30, upon which the bottoms of the side portions of the wall 7" rest, the ash pan 14: being located between them. In this instance, the

bearers 30 are shown in the form of I beams, seated upon timbers or keelsons,but any other preferred form may be employed.

Under the construction above described, a

large amount of grate area and heating surface may be obtained within a comparatively small compass and, except as to the ash pan and steam supply pipe, the boiler is practically self-contained. The segmental space at the upper portions of the heads provides steam chambers from which steam is taken centrally, and with less liability to priming than if lateral drums were employed, and the semi-cylindrical form of the upper portions of the heads and fire chamber gives the boiler a low center of gravity.

I claim as myinvention and desire to secure by Letters Patent The combination, in a steam boiler, of two cylindrical heads, having substantially horizontal axes, inclined water tubes connecting said heads, a fire chamber intermediate between the heads, and alower grate in said fire 5 chamber, substantially as set forth.

In testimony whereof I have hereunto set my hand.

HENRY A. LAUGHLIN. Witnesses:

J. SNOWDEN BELL, WM. H. J ONES. 

